A novel label‐free photoelectrochemical immunosensor was developed for the determination of prostate‐specific antigen (PSA) based on fluorine‐doped tin oxide (FTO) electrode modified with barium titanate and cadmium sulfide (BaTiO₃−CdS/FTO). The photoelectrochemical current density of the BaTiO₃ platform sensitized with CdS for the ascorbic acid (AA) donor molecule was higher than that observed in the absence of CdS. The BaTiO₃−CdS/FTO platform was modified with PSA antibodies to produce the anti‐PSA/BaTiO₃−CdS/FTO immunosensor, which was incubated in solutions of PSA to inhibit the photocurrent density of the immunosensor for AA. The photocurrent density of the anti‐PSA/BaTiO₃−CdS/FTO immunosensor presented a linear relationship with the logarithm of the PSA concentration ranging from 1 pg mL⁻¹ to 1 μg mL⁻¹ with good sensitivity. The proposed method presented an experimental detection limit of 1 pg mL⁻¹ (S/N=3). The immunosensor was successfully employed for the determination of PSA in blood serum samples, with recoveries between 98.7 %–104.4 %.

中文翻译：

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光电化学免疫传感器可灵敏定量使用BaTiO3-CdS的人血清样品中的前列腺特异性抗原

基于钛酸钡和硫化镉修饰的氟掺杂氧化锡（FTO）电极（BaTiO ₃ -CdS / FTO），开发了一种新型的无标记光电化学免疫传感器，用于测定前列腺特异性抗原（PSA ）。用CdS敏化抗坏血酸（AA）供体分子的BaTiO ₃平台的光电化学电流密度高于不存在CdS时观察到的光电化学电流密度。用PSA抗体修饰BaTiO ₃ -CdS / FTO平台，以生产抗PSA / BaTiO ₃ -CdS / FTO免疫传感器，将其在PSA溶液中孵育以抑制AA免疫传感器的光电流密度。抗PSA / BaTiO ₃的光电流密度-CdS / FTO免疫传感器与PSA浓度的对数呈线性关系，灵敏度在1 pg mL ^-1至1μgmL ^-1之间。所提出的方法的实验检测极限为1 pg mL ^-1（S / N = 3）。该免疫传感器成功用于血清样品中PSA的测定，回收率在98.7％–104.4％之间。